Finance Guides
Use this collection when a money question depends on time, rates, recurring payments, or cash-flow assumptions. The guides explain the formula before linking to an interactive calculator.
Loans
How Amortization Works
Learn how loan payments split between principal and interest, why early payments are interest-heavy, and how extra payments change payoff cost.
Read guideInterest
APR vs APY Guide
Compare APR and APY, understand why compounding changes the effective rate, and know which rate to use for loans, CDs, and savings.
Read guideInvesting
Compound Interest Examples
Review compound interest examples for lump sums, recurring deposits, future value, present value, and growth-rate comparisons.
Read guideDebt
Debt Snowball vs Avalanche
Compare debt payoff methods by motivation, interest savings, balance order, APR order, and practical fit for different budgets.
Read guideHow to choose a guide
Start with compound interest for growth over time, amortization for installment loans, APR versus APY for rate comparison, and debt-payoff guides when payment order is the main decision.
Editorial method and source
Finance explanations identify inputs, timing assumptions, compounding conventions, and limitations. They are educational estimates, not personalized financial advice.
Investor.gov financial tools and calculatorsWho maintains this page
Ownership and review
Written and maintained by the Toolarithm editorial team. No review date is shown without a maintained editorial record. No independent professional review is claimed.
Methodology
The editorial team checks definitions, examples, linked tools, and cited references. Dates shown here come from the page's maintained publication record.
Read the editorial methodologyDates and sources
Review dates change only after a substantive method or content check.